Indian vegetable curry

Name: Indian vegetable curry
Cook time: 45 min
Total time: 45 min
Cuisine: Indian
Ingredients: Sunflower oil for frying; 2 red onions, finely sliced; 5cm piece fresh ginger, finely chopped; 1 tsp ground coriander; 1 tbsp garam masala; 1 tsp ground cumin; 2 large maris piper potatoes, cut into 1cm cubes; 1-2 green chillies, finely sliced (optional); 3 garlic cloves, finely chopped; 400g can chopped tomatoes; 500ml vegetable stock; 4 dried kashmiri/Indian chillies, soaked for 10 minutes in boiling water, then roughly chopped; 2 tsp caster sugar; 1 large head broccoli, cut into small florets; 250ml full-fat Greek yogurt; 200g baby leaf spinach; Juice 1-2 limes; Large handful fresh coriander; Flatbreads such as chapatis or rotis to serve